Special CBI judge A K Singh extended the judicial custody of the accused.
The former UP Family Welfare Minister and BSP MLA Jaiswal, who were arrested on March 3, were the first politicians to be arrested in the scam which relates to alleged swindling of over Rs 10,000 crore central funds allocated to the state under the mission.
Kushwaha is accused in the case relating to upgradation of 134 district hospitals for an amount of Rs 13.4 crore by Construction and Design Service, a unit of UP Jal Nigam.
Meanwhile, a special CBI court extended the judicial custody of senior IAS officer Pradeep Shukla, arrested for his alleged role in the NRHM scam, to May 31.
The CBI is likely to file a supplementary chargesheet against Kushwaha and Jaiswal on May 31, sources said.
Under the law, a chargesheet should be filed within 90 days of arrest, and the deadline lapses on May 31 in this case.